TESTING/LIN/ctpt03.f(3)

NAME
TESTING/LIN/ctpt03.f

SYNOPSIS

  Functions/Subroutines
subroutine ctpt03 (uplo, trans, diag, n, nrhs, ap, scale, cnorm, tscal, x, ldx, b, ldb, work, resid)
CTPT03

Function/Subroutine Documentation

  subroutine ctpt03 (character uplo, character trans, character diag, integer n, integer nrhs, complex, dimension( * ) ap, real scale, real, dimension( * ) cnorm, real tscal, complex, dimension( ldx, * ) x, integer ldx, complex, dimension( ldb, * ) b, integer ldb, complex, dimension( * ) work, real resid)

CTPT03

Purpose:

    !>
    !> CTPT03 computes the residual for the solution to a scaled triangular
    !> system of equations A*x = s*b,  A**T *x = s*b,  or  A**H *x = s*b,
    !> when the triangular matrix A is stored in packed format.  Here A**T
    !> denotes the transpose of A, A**H denotes the conjugate transpose of
    !> A, s is a scalar, and x and b are N by NRHS matrices.  The test ratio
    !> is the maximum over the number of right hand sides of
    !>    norm(s*b - op(A)*x) / ( norm(op(A)) * norm(x) * EPS ),
    !> where op(A) denotes A, A**T, or A**H, and EPS is the machine epsilon.
    !>

Parameters
    UPLO

    !>          UPLO is CHARACTER*1
    !>          Specifies whether the matrix A is upper or lower triangular.
    !>          = 'U':  Upper triangular
    !>          = 'L':  Lower triangular
    !>

    TRANS

    !>          TRANS is CHARACTER*1
    !>          Specifies the operation applied to A.
    !>          = 'N':  A *x = s*b     (No transpose)
    !>          = 'T':  A**T *x = s*b  (Transpose)
    !>          = 'C':  A**H *x = s*b  (Conjugate transpose)
    !>

    DIAG

    !>          DIAG is CHARACTER*1
    !>          Specifies whether or not the matrix A is unit triangular.
    !>          = 'N':  Non-unit triangular
    !>          = 'U':  Unit triangular
    !>

    N

    !>          N is INTEGER
    !>          The order of the matrix A.  N >= 0.
    !>

    NRHS

    !>          NRHS is INTEGER
    !>          The number of right hand sides, i.e., the number of columns
    !>          of the matrices X and B.  NRHS >= 0.
    !>

    AP

    !>          AP is COMPLEX array, dimension (N*(N+1)/2)
    !>          The upper or lower triangular matrix A, packed columnwise in
    !>          a linear array.  The j-th column of A is stored in the array
    !>          AP as follows:
    !>          if UPLO = 'U', AP((j-1)*j/2 + i) = A(i,j) for 1<=i<=j;
    !>          if UPLO = 'L',
    !>             AP((j-1)*(n-j) + j*(j+1)/2 + i-j) = A(i,j) for j<=i<=n.
    !>

    SCALE

    !>          SCALE is REAL
    !>          The scaling factor s used in solving the triangular system.
    !>

    CNORM

    !>          CNORM is REAL array, dimension (N)
    !>          The 1-norms of the columns of A, not counting the diagonal.
    !>

    TSCAL

    !>          TSCAL is REAL
    !>          The scaling factor used in computing the 1-norms in CNORM.
    !>          CNORM actually contains the column norms of TSCAL*A.
    !>

    X

    !>          X is COMPLEX array, dimension (LDX,NRHS)
    !>          The computed solution vectors for the system of linear
    !>          equations.
    !>

    LDX

    !>          LDX is INTEGER
    !>          The leading dimension of the array X.  LDX >= max(1,N).
    !>

    B

    !>          B is COMPLEX array, dimension (LDB,NRHS)
    !>          The right hand side vectors for the system of linear
    !>          equations.
    !>

    LDB

    !>          LDB is INTEGER
    !>          The leading dimension of the array B.  LDB >= max(1,N).
    !>

    WORK

    !>          WORK is COMPLEX array, dimension (N)
    !>

    RESID

    !>          RESID is REAL
    !>          The maximum over the number of right hand sides of
    !>          norm(op(A)*x - s*b) / ( norm(op(A)) * norm(x) * EPS ).
    !>

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 160 of file ctpt03.f.

Author

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